Algae & Phosphate Removal

Lanthanum Chloride (LaCl3) is used for treatment in aquariums, water parks, residential waters as well as in aquatic habitats for the prevention of algae growth. Lanthanum is a rare earth metal that is very effective at preventing build up of phosphate in water. In the form of Lanthanum Chloride a small dose introduced to phosphate laden water immediately forms small flocs of LaPO4 precipitate which can then be filtered using a sand filter.

LaCl3 is especially effective in reducing very high  phosphate concentrations.

Lanthanum (III) Chloride - LaCl3


  • Removes phosphate down to <10 ppb (<0.01 mg/L)
  • Hinders growth of algae due to low phosphate level
  • Will not discolor the water system
  • Enables reduced chlorine usage for algae control

Product Specifications

The solution is 28% TREO (Total Rare Earth Oxide).
Specific Concentration: Lanthanum (III) Chloride 28% TREO solution, 99% La2O3/TREO

LaCl3 Specifications

TREO >= 27%, <= 29%
La2O3/TREO >= 99%
CeO2/TREO reported on COA
Pr6O11/TREO reported on COA
Nd2O3/TREO reported on COA
Na2O reported on COA
SiO2 reported on COA
pH 3.0 - 5.0

Ecologix Environmental Systems offers two rare earth chloride solutions that are used for phosphate abatement: lanthanum chloride and cerium/lanthanum chloride (CLC). Both solutions are very effective at removing phosphates from water due to their high affinity for phosphorus and wider effective pH range. Each product reacts with phosphorus in a 1:1 molar ratio, which reduces the amount of solution needed to achieve the desired phosphate level and produces less sludge.

Ecologix sells lanthanum chloride to customers in the zoo, aquarium, and swimming pool industries. One zoo that uses lanthanum chloride has had excellent results in their sea lion exhibit. The solution removed enough phosphorus to reduce algal growth and served as a filter aid, resulting in clearer water in the tank. Another customer purchases lanthanum chloride to control algal growth in swimming pools.

CLC is a newer product than Lanthanum Chloride. It has been used in the wheat, gluten and starch industry. CLC is used to treat the water leaving these production facilities.


The rare earths as a group tend to have LD50’s above 3,000 mg/kg, classifying them as moderately or slightly toxic. Even though rare earth elements may cause skin and eye irritation, they are generally poorly absorbed through the gastrointestinal tract, skin and lungs.1 The acute toxicity of both cerium and lanthanum has been studied and was found to be low.1 As of 2014, the EPA has not classified any rare earth elements as carcinogens.

The EPA has derived Provisional Peer Reviewed Toxicity Values (PPRTV) for lanthanum and cerium compounds. PPRTV is a toxicity value derived after a review of relevant scientific literature using the same methods used by the EPA Integrated Risk Information System (IRIS) Program.